title: Childhood-onset systemic lupus erythematosus in Croatia: demographic, clinical and laboratory features, and factors influencing time to diagnosis.
abstract: OBJECTIVE
  Childhood-onset systemic lupus erythematosus (cSLE) presents with diverse clinical features and often with non-classical symptoms that may delay diagnosis and increase risk of morbidity and mortality. This paper aims to analyse incidence, and clinical and laboratory features of cSLE in Croatia between 1991 and 2010, and to identify factors influencing time to diagnosis.
  
  
  RESULTS
  Medical records at three university-based tertiary care centres were analysed retrospectively for 81 children with cSLE (68 girls). Mean age at onset was 13.4±2.8 yr (interquartile range 3), and annual incidence varied from 1-15 per million at risk. The most frequent clinical and laboratory features were musculoskeletal symptoms (80%) and increased erythrocyte sedimentation rate (96%). The most frequent immunological laboratory findings were the presence of antibodies against histones (86%), double-stranded DNA (73%), and Sm protein (64%), as well as low levels of C3 complement (69%). Haematuria was present in 58% of children, proteinuria in 56%, and biopsy-confirmed lupus nephritis in 43%. Median time from symptom onset to diagnosis was 2 months (range 0-96). Time to diagnosis was inversely associated with ECLAM score (p<0.001), but it showed no association with age, gender, clinical features or distance from the nearest paediatric centre.
  
  
  CONCLUSIONS
  This is the first large-scale, in-depth study of clinical and laboratory features of cSLE in Croatia. Among all demographic, laboratory and clinical features examined, ECLAM score alone was inversely associated with time to diagnosis. This highlights the need to improve detection of children with fewer symptoms early in the course of the disease, therefore serious consequences for prognosis could be avoided.
authors.affiliation: Department of Paediatrics, University Hospital Centre Zagreb, University of Zagreb School of Medicine, Zagreb, and Department of Anaesthesiology, Reanimatology and Intensive Care, Varazdin General Hospital, Varazdin, Croatia. lukic.anita@yahoo.com.
authors.forename: Anita
authors.initials: A
authors.lastname: Lukic
authors.forename: Ivan Kresimir
authors.initials: IK
authors.lastname: Lukic
authors.forename: Ivan
authors.initials: I
authors.lastname: Malcic
authors.forename: Danica
authors.initials: D
authors.lastname: Batinic
authors.forename: Danko
authors.initials: D
authors.lastname: Milosevic
authors.forename: Vojko
authors.initials: V
authors.lastname: Rozmanic
authors.forename: Marijan
authors.initials: M
authors.lastname: Saraga
authors.forename: Mirna
authors.initials: M
authors.lastname: Subat-Dezulovic
authors.forename: Vitomir
authors.initials: V
authors.lastname: Metlicic
authors.forename: Branko
authors.initials: B
authors.lastname: Malenica
authors.forename: Marija
authors.initials: M
authors.lastname: Jelusic
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D016009:Chi-Square Distribution; D002648:Child; D017523:Croatia / Q000453:epidemiology; D057210:Delayed Diagnosis; D005260:Female; D006801:Humans; D015994:Incidence; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology* / Q000276:immunology; D008297:Male; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D062606:Tertiary Care Centers; D013997:Time Factors